An easier way to set VTF/VTA/SRA? Perhaps....

Hi, Nsgarch, the use of weighted cantilever angle would not add to the confusion but rather eliminate the use of SRA/VTA since both of these alignment parameters are nearly impossible to measure, especially VTA. Your description of how to find optimal SRA is, unfortunately, unrealisitic when considering the range of stylus geometries and the need for high magnification to actually see the stylus.

We actually agree on several aspects of cartridge alignment and your comments reinforce my belief that we need a more simple and easily measured parameter.

Tom

Tom -- finding true vertical for a line or micro-ridge stylus, as I outlined, is actually quite easy, and many people have done it with great results once it was explained. And there are only three stylus geometries, if what you mean by "geometries" is stylus 'shapes'. There are: spherical, elliptical, and line/micro. There was also the Shibata which was an attempt at making a line-contact but before laser cutting techniques were available. After finding zero SRA, it's nice but not mandatory, to have an arm with vertical height adjustment "on the fly" (while the record is playing) so you can experiment easily once you know where true vertical is for your stylus.

As for your statement

I refer to it as Weighted Cantilever Angle (WCA) which is the angle of the cantilever (from horizontal) where the manufacturer intended the cantilever to be positioned within the cartridge generator.

I think you are using the wrong terms, which is what's getting you into conceptual trouble. It's not the CANTILEVER which is positioned WITHIN the generator -- since the GENERATOR consists of the coil/armature positioned inside the magnetic field. The cantilever is completely outside that area. And frankly, I don't think cartridge makers are much concerned with cantilever angle, so long as it allows the cartridge body and front pole piece to clear the record surface. What cartridge makers ARE interested in doing is making the cantilever as SHORT as possible to eliminate resonances. The van den Hul Colibri doesn't even HAVE a front pole piece in order to facilitate an EXTREMELY SHORT cantilever. And DECCA cartridges have no cantilever whatsoever!

I truly wish people would stop using that "SRA/VTA" term as if they are the same thing -- THEY ARE NOT!! Further, VTA can be pretty much any angle between too low (the back of the cartridge hitting the record) and too high (the front of the cartridge or front pole piece hitting the record) and so what!? What IS important, is to let the VTA chip fall where it may, while instead MAKING SURE the stylus' edges slant forward at exactly the same angle as the forward-slanting groove undulations - thus locking them together.

Sorry for the long post but I'm afraid we have little to agree on at the moment ;-)

Neil
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Neil, thanks for the explanation. And for being tolerant of my misunderstanding of the relationship of the cantilever and generator. (The few schematics I've been able to find are crude representations at best.)

My original thought on the use of cantilever angle had more to do with setting proper stylus rake angle, as installed by the manufacturer. Using SRA as a measurement parameter is possible but not easily measured. Your procedure is certainly an improvement but still requires more effort than many vinyl lovers are willing to undertake. I wanted something quick and easy. :-)

In considering the use of cantilever angle, I assume that the stylus is properly mounted to the cantilever and that the manufacturer knows the angle of the cantilever when the stylus is at an optimal rake angle. Wouldn't it be much easier to measure the angle of the cantilever rather than a tiny stylus? (The exceptions you mention, notwithstanding.) If the process of mounting the stylus to the cantilever is not consistent and the resulting placement is so variable that determining proper SRA is not possible using WCA then this whole idea is a lost cause.

Tom

PS: We may agree on one thing: VTA is a fairly useless parameter. '-) I only included it as part of the collective theme of cartridge alignment.

Well, the cartridge manufacturers do already provide the parameter to set the VTF right: - their recommendation of the range the VTF have to be set in.

We will get no more and there is good reason why.
Aside that there is no monetary reason for the cartridge manufacturer to add any mechanical "helpers" - there too is little need.
Analog cartridges for the high-end customer is a luxury market with highly emotional customers. Nothing to quantify - nothing to determine the quality with any measurable parameters.
Similar to high-priced jewelry (at least there are quantifications like purity of precious metal, carat etc.), high performance cars - you name it.
Its individually viewed AND judged performance and personal preferences.

I guess - as frustrating as this might look on first sight to some - that we are doing quite well the way it is now.
Unfortunately this means that setting up an individual analog cartridge to fully show its abilities will always require skill, knowledge, experience and very precise handwork.

But then most of these are needed in all real passions.

There is hardly ever any free lunch out there.

Cheers,
D.

We all agree that a cartridge usually needs some time to reach its designed for operating conditions (velocity). Furthermore we are looking at a bundle of other depending parameters (tonearm, cable, matching impedances, inductances etc.) in interaction with the cartridge and thus influencing its sonic performance.
Next in line is individual sample differences within a production design.
No two cartridges of a given production design are truly identical in the technical sense nor in their technical parameters.
After all most are hand-trimmed or fine-tuned and so they are similar and go for a similar "family"-sound, but are not identical.

We will always need a range to work within.

I wish I could agree with more of what everyone is saying, but most of it is wishful thinking. For instance

I assume that the stylus is properly mounted to the cantilever and that the manufacturer knows the angle of the cantilever when the stylus is at an optimal rake angle. Wouldn't it be much easier to measure the angle of the cantilever rather than a tiny stylus?

All I can say is I wish it were true but it's not. It's hard enough to mount a stylus to a cantilever. Expecting to mount the diamond at the same angle to the cantilever time after time is simply not possible. Even the solid one-piece diamond stylus/cantilever cannot be fabricated identically time after time. Thus the need for calibrating the initial zero SRA point for each stylus-cantilever assembly. Thaough statistically possible, no two can ever be assumed to be the same. As for

Well, the cartridge manufacturers do already provide the parameter to set the VTF right: - their recommendation of the range the VTF have to be set in.

There's a reason for specifying a 'range' and it's this: there is only one VTF setting for an individual cartridge at which the suspension will compress just the right amount to place the coils at exactly 90 deg. to the magnetic force field. If you look at a mechanical drawing or exploded view of a typical MC cartridge, there is a tension wire attached to the coil armature on the opposite (back) side from where the cantilever is attached. This wire is carefully pulled to a certain tension and locked with a set screw. This "pre-compresses" the suspension rubber; otherwise applying the correct VTF would just collapse the suspension and the cantilever would 'retract' up into the cartridge body ;-) Further, that wire is not pulled straight back, but slightly upward and back, forcing the coil armature to sort of 'tilt' forward and putting a little "downward English" on the cantilever - then, when the stylus contacts the record at the 'perfect' VTF, the suspension compresses and the coil armature tilts backward slightly, bringing it into proper right angle relationship to the force field. It's the trickiest of all the steps in making a cartridge and each cartridge will have a specific VTF setting (within its specified VTF range) where that alignment is correct. As far as I'm concerned, each cartridge has one absolute VTF setting at which this perfect alignment occurs. (It also happens to be the one where the cartridge sounds its best ;-) The SRA setting is not absolute. It will vary +/- a half a degree from the average 1.4 degrees as a result of two factors out of our control: record thickness and the whims of the lathe operator. Which is why SRA on the fly tonearms are preferable. And why I'll either eventually sell my SME V or get so old I just don't give a rat's a-- anymore!

Then you have to get the other geometries right on the money. Overhang, offset angle, azimuth. The only setup parameter that will usually vary (SLIGHTLY) from the theoretical ideal, and therefore a bit open to musical "taste" is cartridge loading. That variability is due to differences in tonearm mass/damping, cables, phono preamps and/or SUT's, or other room and/or hardware factors. It's where you get to tailor (if only slightly) the sound of your cartridge to suit your sonic preferences.

The other settings are pretty much absolute if you take the time to discover them. One can't (or shouldn't!) just go and "de-tune" a cartridge in an effort to change its sound ;-). You can try fooling with loading, cables, pre-preamp equipment, even different tonearms; but finally, if you don't dig the sound, it's just not the cartridge for you.
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